M8 Aerodynamics

Question 1

Disadvantages of swept wings

Answer 1

Reduces lift, swept wings need to be longer, has to be heavier

Question 2

How’s lift created

Answer 2

Created as velocity of air is taken over the wing and therefore the static pressure above the wing decreases when the static pressure below stays the same so there for the pressure below is higher than above which causes lift to occur

Question 3

What’s the Magnus affect

Answer 3

When an cylinder rotates which then increases the speed on the upper surface which then cause# lift due to the static pressure now being lower on top

Question 4

What’s the mean camber line

Answer 4

The curved line that sits halfway between the upper and lower surface

Question 5

What factors affect lift

Answer 5

Icy conditions
Angle of attack
Thickness of profile
Camber line

Question 6

Earths average atmospheric pressure ?

Answer 6

14.7 psi or 1013Hpa

Question 7

How do you calculate wing area

Answer 7

Wingspan x chord

Question 8

How do you calculate Mach number

Answer 8

Speed of aircraft divided by speed of sound

Question 9

What’s centre of pressure

Answer 9

The centre point from where all pressure/force is said to act from

Question 10

Factors that affect drag

Answer 10

Angle of attack and if the aircraft is at a climb

Question 11

What’s the stratosphere

Answer 11

The point from where temperature no longer changes and there are no more clouds

Question 12

What’s the difference between positive and negative sweep wings

Answer 12

Positive wings are facing backwards whereas negative wings are facing forwards

Question 13

Advantages of swept wings

Answer 13

Provides stability
Good for aircraft that want to fly at speeds close to speed of light or over

Question 14

How does altitude affect the speed of sound

Answer 14

The higher the altitude the slower the speed of sound because as the altitude gets greater the temperature decreases which slows down the speed of sound

Question 15

What’s the difference between subsonic, transonic and supersonic

Answer 15

Subsonic is travelling at speeds up to critical Mach
Transonic is the speed of the aircraft that’s travelling at the speed of sound
Supersonic is the speed of the aircraft that’s exceeding the speed of sound

Question 16

What’s critical Mach

Answer 16

Critical Mach is the speed an aircraft can travel at without any parts of the plane exceeding the speed of sound

Question 17

Average world temp in Kelvin

Answer 17

288k

Question 18

Average air density

Answer 18

1.224 kg/m cubed

Question 19

What’s the formula for theoretical lift

Answer 19

P divided by 2 x v squared x a

Question 20

What’s the angle of incidence

Answer 20

Angle between cord line and longitudinal axis of aircraft

Question 21

What’s the angle of attack

Answer 21

The angle between the chord line and the relative wind

Question 22

How do you work out dynamic pressure

Answer 22

One half x density x speed squared

Question 23

How do you work out Static pressure

Answer 23

Density x height x gravity

Question 24

Difference between a anhedral and dihedral

Answer 24

Dihedral is when the wing tips are higher than the wing base
Anhedral is when the wing base is higher than the wing tips

Question 25

What’s air called that’s taken up from the leading edge? What’s air called that’s discharged from trailing edge?

Answer 25

Upwash
Downwash

Question 26

What’s a cord line

Answer 26

The line that goes from the leading edge to the trailing edge

Question 27

What’s fineness ratio

Answer 27

The maximum thickness of a profile expressed as a ratio or a percentage

Question 28

What’s relative wind

Answer 28

The speed and direction of the air acting on an aircraft which it’s passing through

Question 29

What are the two components of aerodynamic forces

Answer 29

Drag and lift

Question 30

What part of atmosphere does weather occur in

Answer 30

Troposphere

Question 31

How far up is the stratosphere from sea level

Answer 31

11km

Question 32

How much does temperature drop by as you go up a km

Answer 32

6.5

Question 33

What happens to static pressure as dynamic increases

Answer 33

Static pressure must decrease and vice versa

Question 34

What’s the stagnation point

Answer 34

The point where velocity of airflow is 0

Question 35

What type of wave is a sound wave

Answer 35

Longitudinal